In a microwave-safe bowl, combine chocolate chips and butter. Microwave in 30 second intervals until smooth.
Place peanut butter cups on parchment paper or silicone baking mat into muffin tin trays.
Drop spoonful of the microwaved mixture over each cup, spreading to form a layer. Melt chocolate with additional 1 tablespoon sugar and pour onto peanut butter base in thin layers until full or desired thickness is achieved (about three).
Freeze for at least an hour before serving.